Research Article
Advances in Animal and Veterinary Sciences
Health Risk Assessment of Heavy Metals for Egyptian Population via Consumption of Poultry Edibles Manal A. M. Mahmoud, Hosnia S. Abdel-Mohsein Department of Animal Hygiene, Faculty of Veterinary Medicine, Assiut University, Assiut 71526 – Egypt.
Abstract | Exposure to heavy metals through poultry consumption may lead to health risks in Egypt, especially in areas with expanding industrial and agricultural activities. Lead (Pb), Cadmium (cd), Aluminum (Al) and Nickel (Ni) concentrations were determined in poultry muscle and liver using ZEEnit 700P Atomic Absorption Spectrophotometer with Graphite Furness. Mean concentrations of Pb and Cd in poultry muscle and liver exceeded the maximum tolerable limit set by the European communities. However, Al and Ni concentrations were below the guideline limits. According to the Egyptian standardization, only 33% and 66% of liver and muscle samples from Assiut exceeded the limit, respectively. The estimated weekly and daily intakes in the examined samples were below the FAO/WHO Guidelines limits. Meanwhile, Target Hazard Quotients (THQ) and Hazard Index (HI) were calculated to estimate the human health risk of Egyptian population. In this study, THQ and HI were more than 1 for Cd when compared with their reference dose (RfD) in poultry edibles from both Assiut and Qena. The study emphasizes the potential public health risk of Cd contamination from poultry consumption to the local inhabitants in Egypt. Keywords | Health risk; Lead; Cadmium; Aluminum; Nickel, Poultry edibles Editor | Kuldeep Dhama, Indian Veterinary Research Institute, Uttar Pradesh, India. Received | November 30, 2014; Revised | December 16, 2014; Accepted | December 18, 2014; Published | December 26, 2014 *Correspondence | Hosnia S. Abdel-Mohsein, Faculty of Veterinary Medicine, Assiut University, Assiut, Egypt; Email:
[email protected] Citation | Mahmoud MAM, Abdel-Mohsein HS (2015). Health risk assessment of heavy metals for Egyptian population via consumption of poultry edibles. Adv. Anim. Vet. Sci. 3(1): 58-70. DOI | http://dx.doi.org/10.14737/journal.aavs/2015/3.1.58.70 ISSN (Online) | 2307-8316; ISSN (Print) | 2309-3331 Copyright © 2015 Mahmoud and Abdel-Mohsein. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
INTRODUCTION
tion to paper, cement, natural gas, light tar, spinning and weaving, as well as non-woven fabric and plastics nvironmental pollution with heavy metals in industries. Egypt derives from rapid industrial growth, advances in agriculture fertilizers and urban human Heavy metal contamination is a major problem of our activities. Pollution by the metal and its by-products environment and they are also one of the major condispersion during production, recycling and disposal taminating agents of our food supply (Gholizadeh et impaired health of the population. According to State al., 2009; Khairy, 2009). Uncontrolled pollution levels Information Service (SIS, 2013) in Egypt; Assiut and particularly in developing countries have drawn more Qena are agricultural as well as industrial provinces. attention to the heavy metal problem. Metals of maAssiut host big industries such as: fertilizers, phar- jor interest in bioavailability studies, as listed by the maceuticals, cement, and petrol. Qena is well known U.S. Environmental Protection Agency are aluminfor Aluminium Complex Factory, which is one of the ium, arsenic, cadmium, chromium, copper, mercury, biggest industrial plants in the Middle East, in addi- nickel, lead, selenium, and antimony (McKinney and
E
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Rogers, 1992). Lead, cadmium, aluminum and nickel were selected, in this study, because of their potential for human exposure and increased health risk. Lead and cadmium are among the main toxic and abundant metals which accumulate in food chain (Dermirezen and Uruç, 2006) and easily absorbed from atmospheric air and from the digestive tract (Krejpcio and Trojanowska, 2000). Exposure to lead may cause kidney and nervous system problems as well as inhibit heme synthesis (Berny et al., 1994). However, cadmium is known to be an endocrine disturbing substance and may lead to the development of prostate and breast cancer as well as kidney and skeletal damage in humans (Saha and Zaman, 2012; Nordberg et al., 2002). Food is unquestionably the main source of aluminium intake. Exposure is unavoidable because of the wide use of this element in day-to-day life and in industry. For many years, aluminium was not considered a health threat because of its relatively low bioavailability. In 1965, animal experiments suggested a possible connection between aluminium and Alzheimer’s disease; the findings of Alfrey were the first to establish a connection between neurologic diseases of dialysis patients (Alfrey et al., 1976). In addition, Aluminum is well known as a neurotoxicant and has been shown to have deleterious effects on skeletal and hematopoietic systems of humans (Domingo, 1995). Nickel is a known hematotoxic, immunotoxic, hepatotoxic, pulmotoxic and nephrotoxic agent. Nickel confirms lethal if it surpasses the allowed amount in edibles (Nriagu and Pacyna, 1988).
Advances in Animal and Veterinary Sciences production has trended upward over the last 40 years. Rising demand for poultry meat pushed poultry to 44.3 percent of total domestic production (Taha, 2003). Relatively low and competitive prices as well as dietary and nutritional properties, compared to other meats, are main factors explaining poultry meat’s attractiveness. The increasing demand of food safety has accelerated research regarding the risk associated with food consumption contaminated by heavy metals (Mansour et al., 2009). Estimation of the potential risks to human health through the target hazard quotient method (THQ) associated with intake of heavy metals via consumption of poultry is a must for Egypt ian population safety. Although the THQ -based risk assessment method does not provide a quantitative estimate of the probability of an exposed population experiencing an adverse health effect, it does provide an indication of the risk level associated with pollutant exposure. This method of risk estimation has recently been used by many researchers and has been shown to be valid and useful (Akoto et al., 2014; Saha and Zaman, 2012; Wang et al., 2005; Chien et al., 2002). In Egypt, chicken muscle and liver are a major source of animal protein to the population and are widely consumed. Consequently, The Egyptian population face challenges related to food quality and safety. According to our best knowledge health risk assessment of heavy metals for Egyptian population via consumption of poultry edibles is not reported. Additionally, there is no available data about Al levels contaminating poultry muscles or liver. The present work aimed to determine the concentration of heavy metals (Pb, Cd, Al and Ni) in the liver and muscle of poultry collected from Assiut and Qena in Egypt. Although muscle tended to accumulate low concentrations of metals, it is important to compare their levels to the known guideline safe levels because muscle constitutes the greatest mass of the poultry that is consumed. It is also necessary to assess the potential health risk of heavy metals to local residents by poultry edibles consumption.
The World Health Organization (WHO) reported that about a quarter of the diseases facing mankind today occured due to prolonged exposure to environmental pollution (UNEP, 2008). The number of Egyptian population with kidney failure, due to heavy metal exposure, is about 35000 and the incidence rose scary as it exceeding 4% at a rate of 500 patients per million populations (Abdalla, 2012). In addition, the prevalence of renal failure, liver cirrhosis, and chronic anaemia diseases was markedly increased among the MATERIAL AND METHODS Egyptian population in the last few years due to environmental pollution with high exposure to metal poi- Sample Collection and Preparation soning (Salem et al., 2000). Forty eight liver and thirty six muscle samples were collected from broiler poultry farms in Assiut and Poultry is a more efficient feed converter and has a Qena Provinces. Assiut farms are private farms with shorter production cycle than red meat animals. Re- capacity ranged from 3000 to 4000 birds. While, Qena sponding to increased demand, Egypt’s poultry meat farms are governmental farms with 15000-20000 January 2015 | Volume 3 | Issue 1 | Page 59
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birds’ capacity. The samples were collected from 3542 days –old age birds. Collected samples were transported in an ice box to the laboratory then kept at -20°C until analysis. All laboratory equipments and containers were washed with Nitric acid 10% solution prior to each use to ensure cleaning. About 5-6 gm of each tissue sample was cut into small pieces and dried in hot air oven at 80°C until reaching a constant weight. The dried tissues were homogenized and grinded to a powder. One gram of each dry sample was weighed, transferred into screw caped glass bottle and 3 ml of nitric acid high grade (68%) (Merck KGaA, 64271 Darmstadt, Germany) was added and the mixture was left overnight at room temperature. Digestion was completed in a water bath at 90°C for about 1-2 hour until the tissue completely dissolved and the solution become clear (Al-Weher, 2008). The digests was allowed to cool, filtered through Whatman (Ashless no. 42) filter paper, then transferred to 25ml volumetric flask and made up to mark with deionized water. Metal analysis (Pb, Cd, Al, and Ni) was carried out in the Central Laboratory of the Faculty of Veterinary Medicine; Assiut University using a ZEEnit 700P Atomic Absorption Spectrophotometer with Graphite Furness Unite (AASG).
Sample Analysis
Aqueous standard stock solutions were prepared for Pb, Cd, Al, and Ni using appropriate salts (Merck KGaA, 64271 Darmstadt, Germany). Working calibration standards of Pb, Cd, Al, and Ni were prepared by serial dilutions of concentrated stock solutions of 1000 mg/L. Four working standards were prepared in triplicate for each metal by serial dilution of the stock solution. These standards and blank solution were aspirated into AASG as described by the manufacturers to obtain the absorbance of each of the samples. A calibration curve for the absorbance versus concentration of the standard metal concentrations was prepared for each metal from which calibration graph for each of the metals in the sample was determined as described by Nnaji et al. (2007).
Quality Control and Recovery Determination
Advances in Animal and Veterinary Sciences tinctly detectable above, but close to blank absorbance measurement (USEPA, 1983). In addition, a recovery study of the total analytical procedure was carried out for metals in selected muscle samples by spiking analysed samples with different concentrations of aliquots of metal standards (a multi-element standard solution) and then reanalysed the samples. All determinations were replicated three times. In order to determine the reliability of instruments, a blank and known standard were run after every 10 samples. Acceptable recoveries for the metals were 104.3% for Pb; 89.8% for Cd; 85.3% for Al and 107.1% for Ni. Heavy metal concentrations are expressed on a dry tissue basis and given as µg/gm dry weight (µg/g d wt). Calculated moisture content of the muscle and liver samples were 73.6%± 261 and 74.7± 2.7%, respectively.
Determination of Target Hazard Quotients (THQ)
Health risk to Egyptian population from poultry intake was characterized by Target Hazard Quotient (THQ). This is the ratio between the exposure and the reference doses (RfD). Rfd represents reference oral dose that is an estimation of the daily exposure of a contaminant to which the human population may be continually exposed over a lifetime without an appreciable risk of harmful effects (Akoto et al., 2014). RfD value for Pb, Cd, Ni and Al is 0.004, 0.001, 0.02 and 1(µg/g bw/day) respectively (USEPA, 2006). The population will pose no risk if the ratio is less than 1 and if the ratio is equal or greater than 1 then population will experience health risk. The following equation is used (Chien et al., 2002):
Where THQ is the target hazard quotient; EF is exposure frequency (365 days/year); ED is the exposure duration (70 years, average lifetime); FIR is the food ingestion rate (g/day); C is the heavy metal concentration in poultry (µg/g); RfD is the oral reference dose (mg/kg/ day); BW is the average adult body weight (70 kg); and AT is the averaging exposure time (365 days/ year × number of exposure years, assuming 70 years).
Hazard Index (HI)
The detection limit for each metal was calculated as To evaluate the potential risk to human health through double the standard deviation of a series of measure- more than one heavy metal, the hazard index (HI) has ments of a solution, the concentration of which is dis- been developed (USEPA, 1989). The hazard index is January 2015 | Volume 3 | Issue 1 | Page 60 NE Academic
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Advances in Animal and Veterinary Sciences
Figure 1: Mean concentration of heavy metals Pb, Cd, Al and Ni expressed as µg/g d wt in (a) liver samples and (b) muscle samples from Assiut and Qena broiler farms. abc: means with different letters are significantly different (p
